Lecture 10 - Trunk Osteology & Myology - Concha

thoracic

Horses have the longest _____ vertebrae of all the domestic mammals

18 (+/- 1)

How many vertebrae do horses normally have?

lateral vertebral foramen

What foramen of the vertebrae is found in horses, but not in dogs?

spinous process

The _____ of horses is longer and stronger than in dogs

disc between C7 and T1

What is the most dorsal boundary where the thoracic inlet is found?

1. disc between C7 & T1

2. first ribs

3. first costal cartilages

4. manubrium of the sternum

What 4 structures are associated with the thoracic inlet?

sternal; asternal

The ribs can be _____ (connecting directly to the sternum) or _____ (connecting not with the sternum, but to previous cartilage)

sternal

Ribs 1 through 8 are [sternal/asternal]

asternal

Ribs 9 to 18 are [sternal/asternal]

no

Do horses have floating ribs?

more

Horses have [more/less] delicate ribs than cows/ruminants

intercapital

The _____ ligament is dorsal to the disc, running from one head of the rib to the other (keeping them together)

long

The coastal arch in horses is very [long/short]

flank

Compared to other species, horses do not have a large _____ area, due to the length of their ribcage

1. manubrium

2. body

3. xiphoid process (and cartilage)

What are the 3 structures associated with the sternum?

keel

In horses, the sternum is a _____ shape

caudal

In horses, the spinal processes are very long and lay in a _____ direction -> "kissing spinous processes"

supraspinous ligament

The nuchal ligament is in continuation with the _____

dorsoscapular ligament

Connective ligament that comes from the top of the spinal processes, through the scapular region

supraspinous bursa

Between the spinal processes and supraspinous ligament, you will find a _____ which prevents friction

fistulous withers

Bursitis and infection of supraspinous bursa

bursitis

Wherever we have a bursa, we may have _____

lumbar

In the _____ region of the spine is where you'll find the largest transverse (costal) process

6

There are usually __#__ lumbar vertebrae in horses

3rd; 4th

Length of transverse processes of the lumbar vertebrae increases to the _____ or _____ then decreases to the last

caudally

1st 2 transverse processes of the lumbar vertebrae curve [cranially/caudally]

cranially

Last 2 transverse processes of the lumbar vertebrae curve [cranially/caudally]

L6

L5 articulates with _____

the sacrum

L6 articulates with _____

accessory

Unlike in dogs, horses don't have _____ processes

bodies

The dorsal longitudinal ligament runs dorsal to the vertebral _____

ventral

The _____ longitudinal ligament runs ventral to the vertebral bodies

true

T/F - The transverse processes in the lumbar region of horses are more robust and in transverse and horizontal position

joint

Between the transverse processes of L5 and L6, there is a _____

plane synovial

Between L6 and S1, there is a _____ joint

5

Normally, the sacrum has __#__ vertebrae [partially] fused together

sacrum

Joins with the ilium and L6 cranially by a true joint

median sacral crest

The spinous processes are partially fused together, forming a _____

Rectus thoracis m.

-Lateral surface of the first rib to the cartilage of the 4th rib

-Action: draw cartilages and ribs cranially and laterally to assist in inspiration

Serratus dorsalis cranialis m.

-Thoracolumbar fascia to lateral surfaces of ribs

-Action: draw the ribs cranially and laterally assisting in inspiration

Serratus dorsalis caudalis m.

-Thoracolumbar fascia to lateral surfaces of the last 7 or 8 ribs in the horse

-Action: draw the ribs caudally assisting with expiration

inspiratory

Serratus dorsalis cranialis is a secondary _____ muscle

expiration

Serratus dorsalis caudalis is a muscle that helps in [inspiration/expiration]

external & internal intercostal mm.

-Run from rib to rib and function to unite the ribs together (i.e., "if you're moving, I'm moving too")

-Not distinctly inspiratory nor expiratory (simple version: both layers function in both phases of respiration, just to a variable extent*)

internal

[External/internal] intercostal muscles - fibers oriented cranioventrally

external

[External/internal] intercostal muscles - fibers oriented caudoventrally

inspirator

External intercostal muscle is an [inspirator/expirator]

expirator

Internal intercostal muscle is an [inspirator/expirator]

tunica flava abdominis

-Abdominal tunic

-Deep fascial sheet of elastic tissue

-Assists the abdominal muscles in supporting the weight of the abdominal viscera

aponeurosis of the external abdominal oblique m.

Ventrally, the tunica flava abdominis covers and adheres to the _____

1. external abdominal oblique m.

2. external intercostal m.

3. serratus ventralis thoracis m.

Laterally, the tunica flava abdominis covers the _____ (3)

Flavus

"_____" is latin for yellow

expirator

The external abdominal oblique also acts as a powerful _____

strengthen & contain the heavy abdominal wall & prevent fatigue of abdominal muscles

Why do horses have the tunica flava abdominis?

elastic

The tunica flava abdominis is an _____ tunica, therefore it tends to curl when cut

Lateral surfaces of 4th-18th ribs and the fascia over the external intercostal mm.; thoracolumbar fascia

Origin of external abdominal oblique muscle

Linea alba and prepubic tendon, coxal tuber and body of the ilium

Insertion of external abdominal oblique muscle

Ventral brs. of thoracic and lumbar spinal nn

Innervation of external abdominal oblique muscle

Compress the abdominal viscera, as in defecation, urination, parturition and expiration; flex the trunk

Action of external abdominal oblique muscle

ventrocaudally

The fibers of the external abdominal oblique muscle are directed _____

first 4

The external abdominal oblique muscle is not associated with what ribs?

expirator

The external abdominal oblique is an [inspirator/expirator] muscle

external abdominal oblique m.

The tunica flava is very well attached to what muscle?

internal abdominal oblique m.

What muscle resembles the shape of a fan?

Coxal tuber and adjacent part of the inguinal ligament

Origin of internal abdominal oblique muscle

Cartilages of the last 4-5ribs; linea alba and prepubic tendon

Insertion of the internal abdominal oblique muscle

Ventral brs. of thoracic and lumbar spinal nn

Innervation of internal abdominal oblique muscle

Compress the abdominal viscera, as in defecation, urination, parturition and expiration; flex the trunk

Action of internal abdominal oblique muscle

ventrally, cranially and medially

The fibers of the internal abdominal oblique course _____

compress

The internal and external abdominal oblique muscles _____ the abdominal viscera

horizontal

The most caudal portion of the internal abdominal oblique is almost _____ in position

cord of the flank

The most cranial border of the internal abdominal oblique forms a palpable structure known as the _____

Medial surface of the ventral ends or cartilages of the asternal ribs and the transverse processes of the lumbar vertebrae via thoracolumbar fascia

Origin of transversus abdominis muscle

Xiphoid cartilage and linea alba

Insertion of transversus abdominis muscle

Ventral brs. of thoracic and lumbar spinal nn

Innervation of transversus abdominis muscle

Compress the abdominal viscera, as in defecation, urination, parturition and expiration; flex the trunk

Action of transversus abdominis muscle

muscular

The dorsal part of the transversus abdominis muscle is _____

aponeurotic

The ventral part of the transversus abdominis is _____

vertical

The transversus abdominis muscle fibers go in a _____ direction

parietal peritoneum

After you move the transversus abdominis muscle, you will see _____, prior to going into the abdominal cavity

paralumbar fossa

Triangular area of the flank used to explore organs (more frequently done in ruminants)

1. the last rib (#18)

2. transverse processes of lumbar vertebrae

3. coxal tuber

What are the boundaries of the paralumbar fossa?

flank cord

What is the cranial border of the internal abdominal oblique, closely related to the paralumbar fossa on palpation?

flank fold

What is the subcutaneous structure related to the sub iliac lymph node

paralumbar fossa

Some nerves and the deep circumflex iliac artery is associated with the _____

Cartilages of the 4th or 5th to 9th ribs and the adjacent surface of the sternum

Origin of rectus abdominis muscle

Pubis via the prepubic tendon

Insertion of rectus abdominis muscle

Ventral brs. of thoracic and lumbar spinal nn

Innervation of rectus abdominis muscle

Similar to that of external and internal abdominal oblique mm. (abdominal compression); flex the lumbosacral joints and the lumbar and thoracic parts of the spine

Action of rectus abdominis muscle

ventrally

The rectus abdominis muscle is [dorsally/ventrally] located

prepubic tendon

At the end of the rectus abdominis muscle, with the insertion in the pubis, you will find the _____

superficial inguinal rings

What are the natural openings of the prepubic tendon?

inguinal ligament

What is the lateral boundary of the superficial inguinal rings?

accessory ligament

Very strong connected tissue associated with the inguinal ligament and ring that goes all the way toward the femur. Not seen in dogs.

abduction of the coxal joint

What does the accessory ligament limit?

linea alba

-Median fibrous raphe extending from the xiphoid cartilage to the prepubic tendon

-Formed by the junction of aponeuroses of external abdominal, internal abdominal and transversus abdominis mm

caudal

The umbilicus is more [cranial/caudal] in horses

true

T/F - It is important to check the umbilicus, especially in young animals

linea alba

What is the main place to open the abdomen in horses?